As illustrated and described in U.S. Pat. No. 4,078,398, the food freezing tunnel has an improved airflow apparatus, wherein an unhoused centrifugal fan wheel, without a volute, or shroud, is mounted with its axis vertically positioned, so it discharges air radially in horizontal directions, to be subsequently redirected upwardly. This fan arrangement is spaced above the floor of the freezing tunnel, and then vertically above, the side by side freezing coils are positioned. Both the food carrying ever changing run and the return ever changing run of the porous conveyor are vertically aligned above the freezing coils. This floor space saving and excellent freezing airflow, food freezing tunnel continues to effectively freeze food products being delivered to the porous food conveyor. However, the further improvements illustrated and described herein have increased operational times, before complete tunnel defrosting periods and/or module defrosting periods must occur. Also electrical motors and their drives are selectable from those offered at lower cost, and they are operated longer, before more convenient inspection, service, and/or replacement must be undertaken. Moreover, the freezing coils stay clean, as food product residues are collected and disposed of above the locations of the freezing coils, thereby adding to the length of the operation times before shutdowns for cause or for inspection must be undertaken.